Exam 35: Interference

A double slit illuminated with light of wavelength 588 nm forms a diffraction pattern on a screen 11.0 cm away.The slit separation is 2464 nm.What is the distance between the third and fourth bright fringes away from the central fringe?

In a double-slit experiment,the slit separation is 2.0 mm,and two wavelengths,750 nm and 900 nm,illuminate the slits simultaneously.A screen is placed 2.0 m from the slits.At what distance from the central maximum on the screen will a bright fringe from one pattern first coincide with a bright fringe from the other?

Two optically flat glass plates,16.0 cm long,are in contact at one end and separated by 0.0200 mm at the other end.The space between the plates is occupied by oil with index of refraction 1.45.The index of refraction of the glass plates is 1.55.The plates are illuminated at normal incidence with monochromatic light,and fringes are observed.If the dark fringes are spaced 2.00 mm apart,what is the wavelength of the monochromatic light?

Light of frequency 6.00 × 10¹⁴ Hz illuminates a soap film (n = 1.33)having air on both sides of it.When viewing the film by reflected light,what is the minimum thickness of the film that will give an interference maximum when the light is incident normally on it?

Two small forward-facing speakers are 2.50 m apart.They are both emitting,in phase with each other,a sound of frequency 1100 Hz in a room where the speed of sound is 344 m/s.A woman is standing opposite the midpoint between the speakers and is initially 35.0 m from the midpoint.As she slowly walks parallel to the line connecting the speakers,at what angle θ (relative to the centerline coming outward from the midpoint between the speakers)will she first hear no sound?

Light of wavelength 425.0 nm in air falls at normal incidence on an oil film that is 850.0 nm thick.The oil is floating on a water layer 15 cm thick.The refractive index of water is 1.33,and that of the oil is 1.40.You want to add oil so that light reflected off of the top of the oil film will be canceled.What is the minimum distance that you should INCREASE the oil film?

Light is incident normally from air onto a liquid film that is on a glass plate.The liquid film is 164 nm thick,and the liquid has index of refraction 1.60.The glass has index of refraction .Calculate the longest visible wavelength (as measured in air)of the light for which there will be totally destructive interference between the rays reflected from the top and bottom surfaces of the film.(Assume that the visible spectrum lies between 400 and 700 nm.)

Light of wavelength 525 nm passes through two slits separated by 0.500 mm and produces an interference pattern on a screen 7.80 m away.The intensity at the central maximum is I₀.What is the distance on the screen from the center of this central maximum to the point where the intensity due to double-slit interference has fallen to 1/2 I_0?

A thin layer of oil (n = 1.25)is on top of a puddle of water (n = 1.33).If normally incident 500-nm light is strongly reflected,what is the minimum nonzero thickness of the oil layer?

In a double-slit experiment,if the slit separation is increased,which of the following happens to the interference pattern shown on the screen?

A pair of narrow slits,separated by 1.8 mm,is illuminated by a monochromatic light source.Light waves arrive at the two slits in phase,and a fringe pattern is observed on a screen 4.8 m from the slits.If there are 5.0 complete bright fringes per centimeter on the screen near the center of the pattern,what is the wavelength of the monochromatic light?

A puddle of water has a thin film of gasoline floating on it.A beam of light is shining perpendicular on the film.If the wavelength of light incident on the film is 560 nm and the indices of refraction of gasoline and water are 1.40 and 1.33,respectively,what is the minimum thickness of the film to see a bright reflection?

A soap bubble,when illuminated with light of frequency 5.11 × 10¹⁴ Hz,appears to be especially reflective.If it is surrounded by air and if its index of refraction is 1.35,what is the thinnest thickness the soap film can be? (c = 3.00 × 10⁸ m/s)